Prepare as much as you can even on the things that feel unnecessary. It would not hurt to even consider following some of the advice given to those who demand bloodless surgery (like prepping her system for a substantial loss). Besides, that may put your husband more at ease seeing that you are open to alternatives if they work. Most witnesses in my area are terrified of the word "transfusion". Many still do believe that such procedure would give you whatever decease the donor had. Including diabetes. (heard that one myself)
I just had surgery (septoplasty) about a month ago. I don't know what happened to me but when it came down to the final hour (naked in a gown already) I got severely nervous to the point where they had to sedate me to lower my blood pressure. I was ready to quit and walk out of the hospital in the same gown. During this time the nurses came to finish paperwork. One of the many questions asked where whether I would accept a blood transfusion if needed. I immediately said yes but I realized later on that such answer did not come from either side of the blood debate. It was pure and simply a nervous instinct to protect myself. I can not imagine that anyone can make a conscious decision on the matter if it had to be made with just hours to spare and a group of elders surrounding you.